Why did Chromium stop allowing NET::ERR_CERTIFICATE_TRANSPARENCY_REQUIRED to htmlacademy.ru?

Question

Chromium

Good day to all. After reloading the htmlacademy.ru page, the browser gave an error that the connection was not secure. Despite the fact that the page immediately opened in Firefox without problems. What is the problem? Browser privacy settings crashed or something? On a Linux PC Ubuntu 16.04, Chromium Version 53.0.2785.143 Built on Ubuntu , running on Ubuntu 16.04 (64-bit).
Error message
Your connection is not private

Attackers might be trying to steal your information from htmlacademy.ru (for example, passwords, messages, or credit cards).

NET::ERR_CERTIFICATE_TRANSPARENCY_REQUIRED

Answer 1

I turned off CERTIFICATE_TRANSPARENCY in chrome using policy,
added the /etc/chromium/policies/managed/policy.json
file
in which I indicated
{
"CertificateTransparencyEnforcementDisabledForUrls":[ "com"]
}
in accordance with the recommendation

Answer 2

https://sslmate.com/blog/post/ct_redaction_in_chrome_53
https://www.certificate-transparency.org/what-is-ct

Answer 3

I'll tweak it a bit:
{
"CertificateTransparencyEnforcementDisabledForUrls":[ "htmlacademy.ru"]
}